Multiple connection plugs are coming to be used on an ever-increasing scale for producing connections between fluid-powered units, fluid supply systems and fluid receivers and furthermore for producing connections between fluid logic circuits and sensors and loads used therewith. One useful effect produced in this respect is that they take up little space, while on the other hand there is less danger of producing a wrong connection than with systems in which separate fluid lines of hoses are used.
For making a connection between standard fluid terminals of connection plugs and the separate, different fluid terminals of active and passive fluid components, the special geometry and connection position of such components are taken into account by using adapter blocks. Such adapter blocks have fluid connection or terminals on the one connection face at standard positions, whereas on their other face, opposite thereto, they have connection openings or terminals in keeping with the geometry of the component used therewith. Between these two faces there are channels in the body of the adapter block for producing the desired customized connections, such channels being more specially open and uncovered at the face of the adapter block so that the channels have to be covered over by, and fixed tightly against, the component to be worked using fluid supplied by way of the channels, that is to say so that such channels, which in the first place are open on one side, are covered over and in the form of complete ducts as opposed to open channels or grooves.
In the prior art, such adapter blocks have so far been high in price to make. If only a small quantity is produced, the holes and the open channels are produced by machining from a solid block of material (as a rule, a thermosetting resin). Such machining is, however, heavy on highly trained labor and on the use of high-precision machining systems because of the mechanical properties of the resins used; furthermore, the inner or lining faces of the channels are generally rough.
A further point is that such adapter blocks may only be economically produced by injection molding if large production runs are needed because of the high price of injection molds. If the resin used is a thermosetting one, a heavy press is needed to get the desired mold closing pressure and any further machining still needed after molding, for example because of there being a very complex channel geometry, would be high in price, and the brittle material is likely to be chipped. If, on the other hand, a thermoplastic material is used, there will be the shortcoming of uneven shrinkage and furthermore any later machining that may be necessary is hard to undertake.